Page 490 - Flexible Robotics in Medicine

484 Chapter 21
Table 21.4: Metrics table for designing better OmniFlex.

Metric no. Needs addressed Metric Importance Unit
1 1 Strength of forceps 1 Newton (N)
2 1 Size of sample collected 1 mm
3 1 Viability of tissue sample 1 Number of surviving cells
4 2 Range of angulation 1 Degrees
5 2 Degrees of freedom 1 No unit
6 3 Working length 1 cm
7 3 Working diameter 1 mm

Table 21.5: Needs-metrics matrix.
Metric Size of Viability of Degrees
Strength sample tissue Range of of Working Working
of forceps collected sample angulation freedom length diameter
Need
Capable of X X X
collecting tissue
sample
High DOF for X X
maneuverability
Small in X X
dimension

manipulators. For example, the outer diameter of the OmniFlex should be less than the
diameter of existing flexible endoscopic manipulators for the OmniFlex to pass through the
working channel and perform its function. Before conducting benchmarking, the needs and
metrics are identified for proper quantification and comparison of the prototype to existing
devices. Tables 21.3 21.5 illustrate the needs table, metrics table, and needs-metrics
combined table to design and fabricate better OmniFlex prototypes.
Inspired by the ball and socket joint of the shoulder, OmniFlex is undoubtedly intuitive in
terms of handling prototypes. The ability to lock by friction also means that it is a single-
handed procedure, and no twisting of the prototype or awkward arm movement is required
for areas that are hard to reach.

21.5 Design verification tests

21.5.1 Precision test

The precision test is performed to examine the accuracy of proximal control and the distal
actuation. Two circular discs are placed on both the proximal and distal ends to measure the
angle. First, 0-degree angle is calibrated on both ends. The distal end forceps degree is